Control of self-propelled vehicles.



PATENTED AUG. 29.1905.

A. G. DAVIS. CONTROL OF SELF PROPELLED VEHIGLBS.

APPLICATION FILED FEB. 10, 1905.

lnventol Witnesses.

um 00.. mmmumosmmms. WASHINGT n o c UNITED STATES PATENT OFFICE.

ALBERT G. DAVIS, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GEN- ERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

Patented Aug. 29, 1905.

Application filed February 10, 1905. Serial No. 244,998.

To all whom it may concern:

Be it known that I, ALBERT Gr. DAVIS, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Control ofSelf-Propelled Vehicles, of which the following is a specification.

My invention relates to self-propelled vehicles provided withelectromagnetic clutches for controlling the speed; and its object is toprovide novel controlling means for the clutches whereby the flexibilityof control is increased and all shocks due to throwing the power 011'and on quickly at high speeds is eliminated. Electromagnetic clutchespossess certain advantages as power-transmitting mechanism for vehicles,owing not only to the ease of control, but also to the smoothness withwhich transition may be made from one speed to another. When the vehicleis running at full speed, however, and it is desired to throw the powerofi? suddenly, either to coast or to bring the vehicle to rest, it isnecessary with the controlling devices as ordinarily arranged to connectthe low-speed clutches momentarily in circuit in moving the controllerto the off, position, and this tends suddenly to reduce the speed of thevehicle, and thereby to produce a certain amount of shock. By myinvention auxiliary means are provided for opening the circuit of theclutches regardless of the position of the controller, so that it is notnecessary to move the controller through the low-speed positions; butthe circuit may be broken and reestablished without moving thecontroller at all. Thus if the vehicle is running at high speed theprime mover may be instantaneously disconnected from the driving-wheelsand the vehicle allowed to coast. Then the prime mover may be againconnected to the drivingwheels through the same gears as before withoutthe necessity of passing through the low speeds. Thus by my inventionthe flexibility of the control is increased and all shocks in throwingthe power off and on at high speeds are eliminated.

My invention consists in the combination, with the electromagneticspeed-controlling mechanism, of a self-propelled vehicle and thecontrolling-switch therefor, of auxiliary means for breaking theclutch-circuit regardless of the position of the controller.

More specifically speaking, my invention comprises, in combination withthe above elements, a movable member, such as a pedal, provided withcontacts included on the clutchcircuit normally held in closed-circuitposition by a spring or other similar means, but arranged when movedagainst the pressure of the holding means to open the clutch-circuitregardless of the position of the controller.

My invention will best be understood by reference to the accompanyingdrawings, in which" 7 Figure 1 shows a side elevation of a motorcar withtwo wheels removed provided with controlling means arranged inaccordance with my invention, and Fig. 2 is a diagram showing thecircuit connections of the clutches, controller, and auxiliary switch.

In Fig. 1, A represents the frame of the car,

to which are secured in the usual manner the bearings for the wheels W.Supported on the frame A is the prime mover E, which may be of anysuitable type, such as an internalcombustion engine. Mounted on theengineshaft is a small generator G, which supplies power for theclutches and for the ignition devices oi the engine. C represents theelectromagnetic clutches by means of which the prime mover E may beconnected through different speed ratios to the difierential D, and thespeed and torque of the vehicle thereby controlled. These clutches inconstruction and arrangement may be of any well-known type, theparticular form of magnetic clutch employed being in no way essential tomy pres ent invention. The differential D is shown connected to thedriving-wheel N through a sprocket-chain in the usual manner. Frepresents an electric circuit-controller placed con- Veniently foroperation by the driver and arranged to connect the windings of theseveral magnetic clutches successively in circuit with the generator Or,so as to vary the speed and torque of the vehicle at will. H representsa pedal normally held raised in the position shown and carrying contactswhich are included in the clutch-circuit. When the pedal H is depressed,the clutch-circuit is opened. regardless of the position of thecontroller F, but when released its spring returns it to the positionshown, automatically closing the clutch-circuit.

The connections of the circuits are shown in Fig. 2, in which Crepresents the windings of the several clutches which are connected tothe controller F. Gr represents the generator, which is connected,through contacts on the pedal H, to the controller F. I represents aspring, which normally holds pedal H raised, as shown. The pedal carriestwo movable contacts K and K and is provided with five stationarycontacts is to F. With the pedal in its normal position, as shown, thelefthand terminal of the generator Gr is connected, through contact 7a,K, and 7& to ground, while the right-hand terminal is connected throughcontacts in", K, and to the controller F. If pedal H is depressed, theclutch-circuit will be opened regardless of the position of thecontroller F by contact K leaving contact is and contact K leavingcontact As the downward movement of pedal H is continued contacts 71:and will be momentarily connected through contact K, and contacts 70 and71: will at the same instant be connected through contact K. Thisconnects the right-hand terminal of generator G to ground and thelefthand terminal to the controller F, and consequently sendsmomentarily a current in the opposite direction through theclutch-windings 0. This momentary current acts as ademagnetizing-current to insure the complete release of its armature bythe clutch that has been in circuit. As the downward movement of pedal His further continued the clutchcircuit is again and finally broken bycontact K leaving contact k and contact K leaving contact 70". Theclutch-circuit is maintained open as long as pedal H is maintaineddepressed; but whenever the pedal is released spring I will return it toits normal position, closing the clutch-circuit again and againconnecting the prime mover to the wheels without passing through thelow-speed-gear connections.

The construction and arrangement of the auxiliary switch may be modifiedas desired, and the circuit connections of the clutch windings andcontroller may be varied without departing from the spirit of myinvention. A battery may be substituted for the generator G, if desired.

Accordingly I do not desire to limit myself to the particularconstruction and arrangement of parts herein described, but aim in theappended claims to cover all modifications which are within the spiritand scope of my invention.

What I claim as new, and desire to secure by Letters Patent of theUnited States, is

1. In a self-propelled vehicle, a prime mover, magnetic clutches fortransmitting the torque of the prime mover to the wheels of the vehicle,a source of current for energizing said clutches, a circuit-controllerfor connecting the speed and torque of the vehicle, a movable contactmember included in the clutchcircuit and adapted to open said circuitindependently of said controller, and means for holding said contactmember normally in closed-circuit position.

3. In a self-propelled vehicle, a prime mover, magnetic clutches fortransmitting the torque of the prime mover to the wheels 01' thevehicle, a source of current for energizing said clutches, acircuit-controller for connecting said clutches successively to saidsource to vary the speed and torque of the vehicle, a movable contactmember included in the clutchcircuit and adapted to open said circuitindependently of said controller, and a spring for returning saidcontact member to closed-circuit position when released.

4. In a self-propelled vehicle, a prime mover, magnetic clutches fortransmitting the torque of the prime mover to the wheels of the vehicle,a source of current for energizing said clutches, a circuit-controllerfor connecting said clutches successively to said sourceto vary thespeed and torque of the vehicle, and a movable contact member includedin the clutch-circuit adapted to open said circuit independently of saidcontroller and arranged to send a momentarydemagnetizing-current throughthe clutch-circuit when opening said circuit.

5. In a self-propelled vehicle, a prime mover, magnetic clutches fortransmitting the torque of the prime mover to the wheels of the vehicle,a source of current for energizing said clutches, a circuit-controllerfor connecting said clutches successively in circuit with said source tovary the speed and torque of the vehicle, a pedal, aspring for holdingsaid pedal normally raised, and contacts carried by said pedal adaptedto open the clutch-circuit regardless of the position of the controllerwhen said pedal is depressed.

In witness whereof I have hereunto set my hand this 9th day of February,1905.

ALBERT Gr. DAVIS.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

